The objectives of our program of research are to study the different phases of circulatory dynamics and their control. Both normal and abnormal control systems are being studied since many diseases such as hypertension, shock, edema, neurogenic and endocrine disorders, and renal diseases are manifestations of abnormal circulatory control. Our efforts continue to be directed at the development of an overall quantitative mathematical model of the body's circulatory system, which is in accord with both normal physiology and pathological states. The mathematical analysis requires a quantitative description of the different systems and subsystems involved in circulatory control as well as the interrelationships between them. Data for the mathematical model is continually being updated with experimental data from our laboratory. Research is being conducted in two phases. First, the different laboratories within the Program Project are making appropriate measurements of various quantitative relationships within the circulatory system. Second, the data provided from animal experimentation is used to expand and redefine our mathematical analysis--particularly, the current version of the large model of the overall control of the circulation. In turn, the mathematical analyses provide the basis for much of the new animal experimentation. BIBLIOGRAPHIC REFERENCES: Guyton, A.C., A.E. Taylor, R.E. Drake, and J.C. Parker. Dynamics of subatmospheric pressure in the pulmonary interstitial fluid. In: Lung Liquids. (CIBA Symposium). Elsevier-Excerpta Medica, North Holland, Amsterdam, 1976. pp. 77-100. Brace, R.A., A.E. Taylor and A.C. Guyton. Time course of hindlimb lymph protein concentration. Fed. Proc. 35:851, 1976.